Steam, Steel and Electricity

by James W. Steele

It may be well to ask and answer the question that at the first view may seem to the reader almost absurd. What is steel? The answer must, in the majority of instances, be given in accordance with the common conception; which is that it is not iron, yet very like it. The old classification of the metal, even familiarly known, needs now to be supplemented, since it does not describe the modern cast and malleable compounds of iron, carbon and metalloids used for structural purposes, and constituting at least three-fourths of the metal now made under the name of steel. The old term, steel, meant the cast, but malleable, product of iron, containing as much carbon as would cause the metal to harden when heated to redness and quenched in water. It must also be included in the definition that the product must be as free as possible from all admixtures except the requisite amount of carbon. This is "tool" steel. [[7]]

[7.] It must not be understood that tool steel was always a cast metal. In manufacturing, iron bars were laid together in a box or retort, together with powdered charcoal, and heated to a certain degree for a certain time. The carbon from the charcoal was absorbed by the iron, and from the blistered appearance of the bars when taken out this product was, and is known as "blister" steel.

And here occurs a strange thing. A skill in chemistry, the successor of alchemy, is the educational product of the highest form of civilization.

Metallurgy is the highest and most difficult branch of chemistry. Steel is the best result of metallurgy. Yet steel is one of the oldest products of the race, and in lands that have been asleep since written history began. Wendell Phillips in a lecture upon "The Lost Arts,"-- celebrated at the date of its delivery, but now obsolete because not touching upon advances made in science since Phillips's day,--states that the first needle ever made in England, in the time of Henry VIII, was made by a Negro, and that when he died the art died with him. They did not know how to prepare the steel or how to make the needle. He adds that some of the earliest travelers in Africa found a tribe in the interior who gave them better razors than the explorers had. Oriental steel has been celebrated for ages as an inimitable product. It is certainly true that by the simple processes of semi-barbarism the finest tool-steel has been manufactured, perhaps from the days of Tubal Cain downward. The keenness of edge, the temper whose secret is now unknown, the marvelous elasticity of the tools of ancient Damascus, are familiar by repute to every reader and have been celebrated for thousands of years. The swords and daggers made in central Asia two thousand years ago were more remarkable than any similar product of the present for elaborate and beautiful finish as well as for a cutting quality and a tenacity of edge unknown to modern days. All the tests and experiments of a modern government arsenal, with all the technical knowledge of modern times, do not produce such tool-steel. It is also alleged that the ancient weapons did not rust as ours do, and that the oldest are bright to this day. The steel tools and arms that are made in the strange country of India do not rust there, while in the same climate ours are eaten away. Besides the secret of tempering bronze, it would seem that among the lost arts [[8]]--a subject that it is easy to make too much of--there was a chemical ingredient or proportion in steel that we now know nothing of. The old lands of sameness and slumber have kept their secrets.

[8.] Modern science dates from three discoveries. That of Copernicus, the effect of which was to separate scientific astronomy, the astronomy of natural law and defined cause, from astrology, or the astronomy of assertion and tradition. That of Torricelli and Paschal of the actual and measurable weight of the atmosphere, which was the beginning for us of the science of physics, and that of Lavoisier who suspected, and Priestly who demonstrated, oxygen and destroyed the last vestiges of the theory of alchemy. Stahl was the last of these, and Lavoisier the first of the new school in that which I have stated is the highest development of modern science, chemistry. In all these departments we have no adequate reason to assert that we are not ourselves mere students. Some of the functions of oxygen, and the simplest, were unknown within five years before the date of these chapters.

The definition of the word "steel" has been the subject of a scientific quarrel on account of new processes. The grand distinguishing trait of steel, to which it owes all the qualities that make it valuable for the uses to which no other metal can be put, is homogeneity due to fusion. Wrought iron, while having similar chemical qualities, and often as much carbon, is laminated in structure. Structural qualities are largely increasing in importance, and as the structural compounds came gradually to be produced more and more by the casting processes; as they ceased to be laminated in structure and became homogeneous, they were called by the name of steel. The name has been based upon the structure of the material rather than upon its chemical ingredients as heretofore. There is now a disposition to call all compounds of iron that are crystalline in structure, made homogeneous by casting, by the general name of steel, and to distinguish all those whose structural quality is due to welding by the name of iron. [[9]] This is an outline of the controversy about the differences which should be expressed by a name, between tool steel and structural steel. In tool steel there is an almost infinite variety as to quality. The best is a high product of practical science, and how to make the best seems now, as hinted above, a lost art. It has, besides, a great variety. These varieties are only produced after thousands of experiments directed to finding out what ingredients and processes make toward the desired result. These processes, were they all known outside the manufactories of certain specialists, would little interest the general reader. All machinists know of certain brands of tool steel which they prefer. Tool steel is made especially for certain purposes; as for razors and surgical instruments, for saws, for files, for springs, for cutting tools generally. In these there may be little actual difference of quality or manufacture. The tempering of steel after it has been forged into shape is a specialty, almost a natural gift. The manufacture of tool steel, is, as stated, one of the most technical of the arts, and one of the most complicated of the applications of long experience and experiment.

[9.] It should be understood that the shapes of structural and other forms of what we now call steel are given by rolling the ingot after casting, and that the crystalline composition of the metal remains.

Cast steel was first made in 1770 by Huntsman, who for the first time melted the "blistered" steel, which until that time had been the tool steel of commerce, in a crucible. Since that time the process of melting wrought iron has become practical and cheap, and results in crystalline, instead of a laminated structure for all steels. The definition of steel now is that it is a compound of iron which has been cast from a fluid state into a malleable mass.

The ordinary test applied to distinguish wrought iron from steel is to ascertain whether the metal hardens with heating and suddenly cooling in cold water, becoming again softened on reheating and cooling slowly. If it does this it is steel of some quality, good or bad; if not, it is iron.